The present invention relates to signal feedback amplifiers, and more particularly, to feedback amplifiers wherein the closed loop gain of the amplifier circuit is changeable for limiting the output signal voltage independent of power supply voltage levels.
It is often desirable to provide a signal amplifier having a limiting action for preventing overloading of successive stages and the like. In such cases, it is desirable that the limiting be accomplished reliably and economically without introducing appreciable distortion into the signal.
In signal limiting amplifiers, it is desirable that the predetermined limit of output signal of the amplifier remain constant. Often such amplifiers require a regulated power supply for keeping the amplifier limiting threshold constant. Accordingly, it is desirable to provide a signal limiting amplifier wherein the gain and limiting signal levels are independent of power supply voltage.